Multistage turbine in which the rotors are connected by means of differential gear trains



May 22, 1951 J. E. ANDERSON MuLrIs'rAcE TURBINE 1N WHICH THE EoToRs ARE CONNECTED Filed Jan. 29, 1946 INVENTOR JOSEPH E ANDERSON BY H ATTORNEY Patented May 22, 1951 UNI-TED STATES QAVTENT OFFICE MULTISTAGE. TURBINE IN WHICHY THE ROTORSARE CONNECTED BY MEANS,A OF DIFFERENTIAL GEAR`TRAINS Joseph E. Anderson, Maywood, N. J. Application J anuary, 29, 19.46, SerialNo. 643,997l 17 Claims. (Cl. Hilf-70') The present invention relates to multi-stage turbines.

In prior art turbines, the rotor of each stageis mounted on a common shaft so that the" speed of rotation of the. turbine is dependent u pon the rotation thatcan be'developed by the last stage. Thusthe number f, Sieges is limited by the, der sign conditions of thelva'lst stage, the vspeedl of which isv controlled by the energy imparted bythe fluid, Such as Steam? Water 0f. ses' ifzfihe'last 0r W pressure. Stage My invention on the other h and contemplates the provision of aY multi-stage, turbineA in which therotor of yeachstage is mounted on a shaft which is separate from and independent of' any other stage but in whichveach rotor is'operatively interv/mwa@ @that the erger dei/elapsed by each stage' is added to the energy developed by the` succeeding stage. Thus, eachrotor, since it is independent of anyy other rotor, maybe operated at its most emcienttspeed and under the optimum conditions.k

I contemplaten the provision of a multi-stage turbine in which the 'rotor or turbinefwheel is connected through a difierential gear train to the next rotor or turbine wheel'. There` is thereby provided an arrangement in which the speed of rotation of Athe preceding stage'is'added tothe speed of rotation of the succeedingl stage, Vthereby increasing the speed "of the output shaft, which heretofore was the speed of the last or 10W pressure Siagf In prior art multi-stage turbines, there isvprovided betweenl each stage a stationary set vof buckets which` serveto reversethe'direction of ow of the uid exhausted from thev preceding stage before it is directed to impinge on the moving buckets of the succeeding stage since, by reason of the fact that eaoh stage is mounted cna common shaft, the bucketsfof each vstage,'rrlust move in the same direction. Such change in direction absorbs energy' from the fluid which therefore does not perform any, useful work.

My invention on theother handprovideswa construction whereby the. exhaust fron-i one stageis directed in a substantiallystraight path ofvmoi/ efment to impinge tangentially on the rotorY ofthe next stage so. that no' powerjis useessly absorbed by changing theV direction of flowof they fiuidjex'- hausted from any. stage. Thus, the absorption power, 'of each independently operatedrotor is .differentially added'to the-'succeeding rotjij.

' 1i/rinvenire@vertientes amiisias turrbine in which there is provided aplurality of independently, Operating iur-bine Wheel? i@ the first of. which energy from a source of power is received tangentially and converted into rotary motion with the exhaust therefrom passing directlyto the succeedingl turbine wheel to inipinge tangentially thereon'without change of direction.

The present invention stili further oontem.- plates the provision of a multifstag'turbinein which the turbine wheel or impeller of 'the last stage is provided with duplicatesets of blades or buckets set in opposite directions andf having a suitable accumulator leadinginto two separately operatedy controlvalves to permit selectedclockwise or counter-clockwise rotation of the last stage impeller or turbine Wheel shaft.V Thus, by reason of the diiTerential power transmission, the rotation of the,` last stage may be addedforsubtract-ed from the rotation of thel turbine output shaft tol thereby ,provide a: ready means for controlling. the speedof the. multistage turbine output shaftbetween vmaximum and minimum limits.

The present invention maybe appliedto Vimpuise or reactionturbines,y having anyvnumber of Stages, and dfb/@i1 by any. source of powersuch as steam, sas, Water 0 1" thelile! Objects and advantages of the present invention will be clear from the description which follows and from the drawingv appended thereto, which. is schematic, and in which drawing Eig. 1 is a schematic plan view, partially in section of a multi-stage turbine according to my invention;

Fig. 2 is a schematic plan View of the piping diagram therefor. l

In the drawing I have illustrated a five-stage turbine, though it will be understood thatV any lesser or greater number of stages may be utilized.

' The driving fiuid, whether steam, Water or gas, is directed. onto the buckets la of the rst stage rotor. I2,V from an inlet chest or chests indicated by the reference characters. l A4and I6. The rotor i2 of the rst stage is mountedY on the shaft I8 which may be journaled, as in the bearings 20 and 22.

As willbe described in greater detail, the rotor of each stage vis connected to the rotor ofthe succeeding stage by means of a diierential nter?- connecting mechanism such as the mitre gear differential or planetary gear difierential illus'- tratedv in my Co-pending'application Ser. No. 628,903 filedA by me NovemberA 15, '1945, now abandoned, forV power transmission, althoughin thc-:present application I have illustrated my invention with a mitre gear diiierentialru transmission.

`""Ihe rotor. l2y is connected to the diierential 3 housing 24 by means of a suitable reduction gearing, which, for purposes of illustration may be of a forty to one ratio, and which drives the worm gear 26 mounted on the periphery of the housing.

Secured to one face of the housing on the collar 28, I provide the gear 36. Thus, the gear 30 is rotated in the same direction as is the housing 24 that is in the direction of the arrow 32.

It will of course be recognized that the direction of rotation of the housing of any differential is determined by the direction of thread of the driven external housing worm gear and 'that of the intermeshing driving worm gear of the reduction gearing.

Meshing with the gear 30, I provide the gear 34 which is mounted on the shaft 38 journaled in the bearings 38 and 46. Thus, the gear 34 is driven in the direction of the arrow 42 to drive the gear 46, which meshes with it, in the direction of the arrow 48.

The gear 46 is mounted on the shaft 50 which is journaled in the bearing 52. The shaft 58 has mounted on it the gear 54 which rotates in the direction of the arrow 49 and meshes with the gear 56 mounted on the shaft 58 and which is thus rotated in the direction of the arrow 68.

For purposes of illustration, the gears S0, 34, 46, 54 and 56, comprising a train of gears through which the differential housing 24 is operatively connected to the power transmission input shaft 58, are of a one to one ratio, so that the shaft 58 is rotated at the same speed as is the housing 2li.

The shaft 58 is journaled in the bearing 62 and at its inner end, which is positioned inside of the housing 24, has mounted thereon the bevel or mitre gear 64. This bevel or mitre gear 64 rotates in the direction of the arrow 66.

Secured to the housing 24 by means of the shaft 68, on which it rotates= I provide the bevel or mitre gear 10, which is rotated in the direction of the arrow 12.

Meshing with the gear 1I), I provide a third mitre or bevel gear 14, which is mounted on the shaft 16 journaled in the bearing 18 between the housing 24 and the housing 80 which is driven by the second stage rotor 84, as I shall describe.

The gear 14 is thus driven in the direction of the arrow 86 and the housing 24 is carried for free rotation on the input shaft and the output shaft 58 and 16.

By this differential power transmission arrangement, it will be recognized that the rotation of the input shaft 58 is added to the rotation of the housing 24, `developed by the first stage rotor I2; that is the speed of rotation of the output shaft 16 is the sum of the speed of rotation of the housing 24 and the shaft 58.

The power transmission illustrated in the present application is the same as that illustrated in my said co-pending application Ser. No. 628,903, now abandoned, though it will be understood that any other type of gear train or differential transmission may be used.

The mitre gears of the first stage differential power transmission, gears 64, and 14, (and as I shall describe the gears of each succeeding differential power transmission) are preferably of a one to one relation.

In the illustration given, assume that the rst stage rotor I2 operates at 12,800 R. P. M., then because of the forty to one reduction gearing, the housing 24 and so the shaft 58 will operate at 300 R. P. M. Therefore, by reason of the differential power transmission, the output shaft 16 is operated at 600 R. P. M. because it is positively con,-

nected through gearing to the shaft 58 to which the rotation of the differential housing 24 is added.

The exhaust steam or gas from the first stage rotor I2 is directed against the buckets 88 of the second stage rotor 84 through the pipes 90 and 82 and iiows in the direction of the arrow 94. It should be noted that the iirst stage rotor I2 is rotated in the direction of the arrow 96 and the second stage rotor 84 in the same direction as illustrated by the arrow 98.

The direction of rotation of each rotor will be dependent upon the position on its circumference, that is the quadrant at which the driving uid is introduced. I desire to have the steam travel from one rotor stage to the next rotor stage in as nearly a straight line as is possible so that there will not be any change of direction with resulting useless absorption of power. I fur ther desire that the shortest fluid pipe or con-r duit from one stage to the next stage be utilized.

Therefore, a rotor may operate in different directions of rotation, which, since the rotors are independent from each other and the `direction of rotation of any housing may be selected by the proper choice of the driven external housing worm gear and the intermeshing driving Worm gear, will be of no consequence.

In order to obtain such a straight line flow', it is only necessary to provide a pipe construction which preferably assumes the outline of a helical screw thread. This provides an unimpeded, smooth unchanging in direction and uniform travel of the exhaust from the rotor of one stage to the rotor of the next stage.

Thus, a multi-stage turbine is provided whichdoes not change the direction of flow of the driving fluid from one stage to the next stage and vin which the output shaft of each stage will be rotated in the same direction although some of the rotors themselves may be rotated in opposite directions and independently of each other.

The rotor 84 for the second stage is mounted"- on the shaft IIJ!) journaled in the bearings |62' and I04. The differential housing 8D of the second stage is connected to the rotor 84 by means of a reduction gearing, which in the illustration has a forty to one ratio, the last worm gear I06 of which drives the Worm gear I08, secured around the outside of the housing 8B.

There are provided a series of gears joining the shaft 16 to the shaft III! which is journaled in the bearing II2. These gears are the same as those illustrated in the interior of the first stage housing 24 and therefore need not be illustrated further.

It will be seen that the shaft 16 constitutes the output shaft of the first stage and the input shaft of the second stage and the shaft IIU constitutes the output shaft of the second stage and the input shaft of the third stage.

The second stage rotor 84, since it is operated by the exhaust from the first stage, will operate at a speed less than the speed of the first stage rotor I2, say 9,000 R. P. M. Thus the speed of rotation of the second stage differential housing will be 225 R. P. M. By reason of the differential power transmission, this speed of rotation will be added to the speed of rotation of the in put shaft 15, which as pointed out operates at 600 R. P. M., so that the speed of rotation of the second stage output shaft IIIi (which constitutes the input shaft for the third stage) will operate at 825 R. P. M.

The steam, water or gas exhausted from the secondlstage.- rctons directed; to, the buckets |14 ci. th bird'. staseroterY I |15-, through the pipes Llz anda |295- in thej direction ofv the` arrow |225. ThisV rotates the third stage rotor H in tlldi rection of the arrow |2, which byreasonl oi thcfpiping: arrangement is opposite to the-directionogf rotation of the second stage rotor 84.

The third stage rotor H6 is mounted on the shaftY |2, ,whicgh is journaled in the bearingsv |28 and; [3.9. and-drives the differential housing |32 through a. speed reduction gearing (of an assumed forty'toonel ratio), the worm gear |34 of which meshes with the gear |36 on` the housing |;3 2'-. The shaft |38 journaledin thel bearing |40 is; driven byr a similar set orY gears as described for tile rst stage and thus becomes the output for the third stage and the input for the next org fourthV stage.

Thus, in the illustration, the third stage output sha-13138 (which also constitutes the input shaft-oi?A the fourth stage), assuming the third stage rotor` HE operating at 6,000 R. P. M., will rotateat a. speed orf-*975 R. P. the surnof the rotativespeed ofshart (825 R. P. M.) and the rotative speed of the third stage housing |32 (1,50. R. P1 M).

Steam,vk water orgas from the third; stage rotor H6 is directed to the buckets |42V of the fourth stage. rotor |411, which is driven at say a speed-of 3,000, R. P. M, in the direction of the .arrow Id, through the pipes |58 and |50 in the direction, of the arrow |52, The fourth stage rotor is mountedA on the Shaft |54 journaled in the bearings let and |58 andthrough the wor-m gears (and a forty to one reduction gearing;l His, and iii@ drives the differential housing |62 which in turnV by the construction heretofore described drives the shaft Hifi. journaled in the bearing |55.

Thusin the illustration, the fourth stage out.- put shaft` ld (which also constitutes the input shaft` of the iifthv stage, here the last stage), will rotate at av speed of 1050 R. P. M., thesum ofy the rotative speed of shaft |38 (9,75 R. P. ML.) andthe rotative speed ofA the fourth stage housing |62 (75 R. P. M.).

Exhaust from the fourth stagev rotor |44 is directed throughthe pipes |8 and Il!) into the accumulator chest H2., from whichaccumulator chest it is directed to the lastl stage rotor |14. The rotor l-'is provided with two sets of buckets or blades HS. and H8., which buckets or` blades areset in opposite directions.

Thusif: steam, water or gas is directed onto the buckets liti, the rotor Ifi' is operated in the direction of the arrow [BQ but if it is directed onto 'the buckets |15, the rotor |714 will be oper-d ated in the opposite direction illustrated by the arrow |32.

In order to direct the driving; fluid, onto the desired buckets or. blades to control. the speed of the multi-stage turbine output' shaft |34, as will. be described, I arrange between the rotor r'i andthe accumulator chest |'|2, the valves |85 and |88, which permit the driving fluid to be directed onto the selected one of the sets of buckets or blades and shut off from the other set of buckets or blades.

The rotor lili, which is assumed to operate at 150G R. P. M. mounted on the shaft |9|| journaled in the bearings |92 and ld. The rotor |74 is connected to the last stage differential housing |96 by means of a reduction gearing (forty to one) andthe intermeshing gears |98 and 20?. The Shaft |84, Which is journaled in the bearice 213.2-A isconnectedtc. the Shaft |6141 by, means of the mitre gears illustratedjfor therst stage.

Rotation of the rotor Ifilfin one direction Will add its rotativespeedto the speed of the input shaft ltd and ro'tationof the rotor in the opposite directiony will subtract its speed from the shaft llj by reason ofthe differential power transmission, Thus Where there is an addition of the speed, the output shaft |84. will rotate at, a maxim-un or, 1035 R. P. M., the sum of the speedof rotationof the shaft Nid (1050 R. P. M.) the, speed; of; rotation of the housing |96 (3 5 RP. M3) `ridere there is a subtraction of. the Speed, theY output shaft i3d willV rotate at a minimum of 1G15 R, P. M., the difference between the speed ofA rotation of the input shaft ltd' (1050 R. P. M.) and the speed of rotation of the housing |95, inthe opposite direction, (35

"iherefcre, by means ci the accumulator chest,

valyes and oppositely set buckets, the speed oi the output shaft of my muitiwstage turbine may VVrely varied through maximum and minimum imite.,

'nus berecognized that each rotor is functionally independent of any other rotor and each will be driven at the speeds determined by the, energy ofv the uid which impinges on it, which impinge-ment is a tangential4 one.

Each rotor therefore independently adds its absorbed revolutions (and horsepower) differ entially tothe multi-stage turbine output shaft. Thus, if there is. developed 1004 H. P. in the iirst stage, 75 H. P. in the second stage, 5 0 H. P. in the third stage and 25 H. P. in the fourth stage, niy multi-stage turbine will develop 250 H. P. minus mechanical losses and gas velocity losses.

B y the invention here described, the efficiency o f each stage is added to that of the rst stage tc thereby produce a maximum overall efciency, since each rotor is totally independent andwill notabsorb` any load from any other rotor. Thus a true evaluation of the power Valueof exhaust driving fluid can be accurately determined4 since the constructienV described, the exhaust at each stageA can be controlled by venting.

I claim: v

l..` In a multi-stage turbine, a plurality or rotors, eachv rotor connected to a differential power 'transmission comprising an input shaft and` an output shaft, a differential housing lnountedfor free rotation on the said shafts and means carried by the housing for connecting the input shaft to the output shaft, theoutput shaft of; the preceding stagepower transmission constitutingv the input shaft of the succeeding stage power transmissicn, the housing of the first stagepower transmission driving the input shaft Qfthe iirststaee power transmission. the.. outputshaft of the llast stage power transmission constituting. theA output` shaft of the multi-stage turbine. ther rotor of the lastJ- stage having a double rowr of blades set. in, opposite directions and, means for selectively directing the turbine driving fluid onto one of said rows of blades.

2. In a multi-stage turbine, a plurality of rotors mounted independently of each other in the turbine, a differential power transmission connecting the rotor of a preceding turbine stage to the rotor of a succeeding turbine stage and means for connecting the exhaust from the rotor of one stage to the inlet for the rotor of the succeeding stage to direct the exhaust from one stage to the succeeding stage substantially in a straight path of movement and to impinge said exhaust tangentially on the rotor of the succeeding stage without change of direction upon leaving the rotor of the preceding stage.

3. In a turbine, a rotor, a differential power transmission including an input and an output shaft, a housing mounted for free rotation on the shafts and means mounted in the housing for connecting the shafts, means connecting the rotor to the housing and means connecting the housing to the input shaft.

4. In a turbine, a rotor, an input shaft, an output shaft, a differential housing mounted for free rotation on the shafts, a train of gears connecting the input shaft to the output shaft and carried by the differential housing, gear means connecting the rotor to the housing and second gear means connecting the housing and the input shaft.

5. In a multi-stage turbine, a plurality of rotors, each rotor connected to a differential power transmission comprising an input shaft, an output shaft, a housing mounted for free rotation on the said shafts and gear means carried by the housing for connecting the input shaft to the output shaft, the output shaft of a preceding stage power transmission constituting the input shaft of the succeeding stage power transmission, gear means operatively connecting the housing of the rst stage power transmission to the input shaft thereof.

6. In a multi-stage turbine, a plurality of rotors mounted independently of each other, a dif ferential power transmission means connected to the output of each rotor, each differential power transmission means being operatively connected to the input of the succeeding power transmission means and means for connecting the exhaust of a preceding stage to the inlet of a succeeding stage to direct the exhaust from one stage to the succeeding stage substantially in a straight path of movement and to impinge said exhaust tangentially on the rotor of the succeeding stage without change of direction upon leaving the rotor of the preceding stage.

'7. In a multi-stage turbine, a plurality of rotors mounted independently of each other, a differential power transmission means connected to each rotor, each transmission means being operatively connecting to the succeeding power transmission means for connecting the exhaust of a preceding stage to the inlet succeeding stage, said exhaust and inlet connecting means directing the ow of the exhaust from one stage to the next stage in the path of the helical screw thread.

8. In a turbine having a plurality of stages, the rotor of each stage mounted independently of the rotors of the other stages, a differential power transmission for each stage, the output shaft of a power transmission of a preceding stage constituting the input shaft of the power transmission of the succeeding stage.

9. In a turbine having a plurality of stages, the rotor of each stage mounted independently of the rotors of the other stages, a differential power transmission for each stage, the output shaft of 8 l a power transmission of one stage constituting the input shaft of the power transmission of the succeeding stage, and the rotor of the last stage having a double row of blades with a row of said blades being set in the opposite direction of the other row of said blades.

l0. In a turbine, a rotor, a differential power transmission connected to the rotor and comprising an input shaft, an output shaft, a train of gears connecting the input shaft to the output shaft and a housing mounted for free rotation on the said shafts and carrying the said train of gears and gear means connecting the housing t0 the input shaft for driving the input shaft.

1l. In a multi-stage turbine, each stage comprising a rotor, a differential housing connected to and driven by the rotor, an input shaft, an output shaft and a train of gears connecting the shafts and carried in the housing, the output shaft of a preceding stage being common with the input shaft of the succeeding stage and the differential housing of each stage mounted on the input and output shafts of said stage.

l2. The multi-stage turbine of claim 11, the differential housing of the first stage driving the input shaft of said stage.

13. The multi-stage turbine of claim 11, the exhaust of a preceding stage being connected to the exhaust of a succeeding stage.

14. The multi-stage turbine of claim 11, the rotor of the last stage having a double row of blades, each row set in a direction opposite to the other row and valve means for selectively directing the exhaust from the preceding stage to one of the said rows of blades.

l5. In a multistage turbine, a stage comprising a rotor, a differential housing connected to and driven by the rotor, an input shaft, an output shaft and a train of gears carried in the housing and connecting the shafts, the differential housing mounted for free rotation on the shafts.

16. In a multi-stage turbine, a pluraltiy of stages, the rotor of each stage being mounted for rotation independently of any other stage, a differential power mechanism operated by the rotor of each stage, the output of each differential power transmission being connected to the input of the differential power transmission of a succeeding stage, the output of the differential power transmission of the last stage constituting the output of the turbine.

17 The multi-stage turbine of claim 16, means connecting the exhaust of a preceding stage to the inlet of a succeeding stage and directing the flow of the exhaust substantially in a path unchanging in direction.

JOSEPH E. ANDERSON.

REFERENCES CITED UNITED STATES PATENTS Name Date Cake Nov. 22, 1921 Number 

